Reversible polarity mpo fiber optic connector

ABSTRACT

A fiber-optic connector includes a connector body including a housing with a top surface and a bottom surface, the top surface and the bottom surface being joined together by two opposing side surfaces of the housing. The housing has a top slot and a bottom slot thereupon along a longitudinal axis, the top slot and the bottom slot being provided on the top surface and the bottom surface, respectively. A first key structure is slidably positioned within the top slot, and a second key structure is slidably positioned within a bottom.

RELATED APPLICATION

This application is a continuation of U.S. pat. application no.17/671,653 filed on Feb. 15, 2022, issuing on May 30, 2023 as U.S. pat.tno. 11,662,529, which is a divisional of U.S. pat. application no.16/883,156 filed on May 26, 2020, now U.S. pat. no. 11,256,038, which isa continuation of U.S. pat. application no. 16/591,590 filed on Oct. 2,2019, now U.S. pat. no. 10,690,861, which is a continuation of U.S. pat.application no. 15/800,883 filed on Nov. 1, 2017, now U.S. pat. no.10,495,823, which is a continuation of U.S. pat. application no.14/319,132 filed on Jun. 30, 2014, now U.S. pat. no. 9,829,645, allherein incorporated by reference, that application in turn being relatedto U.S. pat. application no. 13/934,378, filed on Jul. 3, 2013, now U.S.Pat. No. 9,046,660.

BACKGROUND Field of the Invention

The present arrangement relates to fiber optic connectors. Moreparticularly, the present arrangement relates to fiber optic connectorswith reversible polarity.

Description of the Related Art

In the area of fiber optic connections, typical fiber optic systemsusually have to establish a bi-directional pathway between a transmitterport on a first element and receiver port on a second element and viseversa. See for example schematic FIG. 1 . In order for such abidirectional systems to function, it is a requirement that one end of afiber be connected to the light emitting source of a first equipment,often a type of laser or light emitting diode, and the other endconnected to a receiver port on a second equipment. For the second fiberin the bi directional pathway, the other fiber needs to be connected tothe light source on the second equipment and, at the other end, thereceiver port of the first equipment.

Fiber optic connectors used for larger high-speed fiber optic systemsoften use multi-fiber cables supporting many bi-directional pathways. Inone example the cables typically have 12 fibers in the cable, with thecorresponding connectors for such cables housing multiple fiber opticmembers within the same connector body. Such a twelve fiber arrangementcan support six of such bi-directional (duplex) pathways.

These connectors used for such high-speed fiber optic systems oftenemploy what are termed multiple fiber optic members, called MPO(Multiple-Fiber Push-On/Pull-off) connectors and they typically supportthe twelve fiber (six duplex channel) arrangements within the sameconnector body.

Using FIG. 1 showing a single two way channel, there can be manysegments of fibers between two components, each representing a fiberoptic cable with a connector. In some cases, between segments, thefibers in the connector of a first segment pass directly across to thefibers of the second segment. However, in some cases, in order for thetransmission signal to end up at the correct receiver port, at least onesegment connection, the connectors must have the pin/fiber input/outputon one side flipped so that the transmission signal exits on the otherfiber in the channel.

This situation is referred to as connector “polarity” for each segment.A fiber cable segment with two connectors at either end that result inthe same polarity across the segment is referred to as method A and afiber cable segment with two connectors at either end that result in aflip in the polarity across the segment is referred to as method B. InFIG. 1 , the first four segments are method A polarity, the fifthsegment is method B polarity exhibiting a flip in the light pathwaysacross the two fibers. Depending on the various fiber optic equipmentarrangements, in the prior art, to make the correct connections, theinstaller needs to select cable segments (i.e. pre-terminated lengths ofcable) that have the correct polarity.

This holds true for larger MPO connectors where the associated cablesmust still also eventually result in one end of a fiber being connectedto a source and the other end connected to a receiver and vice versa foreach bi-directional pathway supported. As shown in FIG. 2 , the topshows Method A polarity where the blue fiber starts on position 1 on oneconnector on one side of the segment and is at the same location(position 1) on the other connector on the other side of the segment.This method A polarity arrangement would be a straight forwardconnection that passes the same connection polarity to the next segmentof the installation.

The bottom part of FIG. 2 shows Method B polarity where the blue fiberstarts on position 1 on one connector on one side of the segment and isat the opposite location (position 12) on the other connector on theother side of the segment. With Method B polarity the remaining fibersin the connector on the second side of the segment are all alsotransposed in position vis-à-vis the first connector. The management ofconnections in such MPO connectors between sources and receivers and thepolarity of such connections is described in the standard TIA-568-C.3.This method B polarity arrangement would be a connection that reversesthe connection polarity going forward to the next segment of theinstallation.

As shown in FIG. 1 , in order for the light signal from one source toreach a receiver at the other end there typically must be an odd numberof ‘flips’ in the cabling, where a ‘flip’ indicates a method B polaritysegment, so that the fiber in connector position 1 is connected toposition 2 on the other side, the fiber in connector position 2 isconnected to position 1 on the other side, etc....

These flips can be achieved via individual fiber assemblies and/or inthe adapters that connect different fiber optic cabling segmentstogether for example as shown in the basic design in FIG. 1 at segment5. However, since fiber optic networks are dynamic environments,connections are often added or subtracted and, as such, the number ofrequired flips changes within the cabling arrangement between equipment.Ensuring that there are an odd number of flips then requires one or moreof the fiber optic assemblies’ polarity to be changed as the connectionsare added or subtracted. This requires the installers and/or end usersto stock assemblies of different polarities and lengths for everypossible network configuration, given that assemblies are pre-terminatedwith a fixed polarity.

For example, the polarity of fiber optic systems is carefully consideredduring the design phase and is generally fixed upon completion becausemany patch cords come pre-terminated and the polarity of theconnector(s) is set at manufacture. For example a patch cord havingconnectors for its end set at a first polarity (i.e. method A or methodB) can only be used for example in FIG. 1 at certain segment locations.If for any reason the configuration changed, as will be explained inmore detail below, the installer may require a new patch cord, possiblyof a different length, and having its two connectors set at a differentpolarity. Consequently, end users must carry a large inventory ofpre-terminated assemblies or order additional parts to allow forreconfigurations of the network topology.

The polarity of an MPO (Multiple-Fiber Push-On/Pull-off) styleconnector, whether it be method A or method B is determined by therelationship between the fibers and a “key” on the connector body, whichis why polarity is sometimes referred to as “keying.”

Prior art FIG. 3 shows a standard prior art MPO connector that has asingle fixed key on its body. Thus, the polarity is set at the time ofmanufacture. Although some prior art arrangements have the ability tochange the key/polarity of the connector, these solutions require thedisassembling and reassembling of existing assemblies or the purchase ofnew assemblies. This increases either labor costs or material costsassociated with these networks/connectors.

OBJECTS AND SUMMARY

The present arrangement overcomes the drawbacks associated with theprior art and provides for a reversible polarity MPO type connector thatcan be applied without worry of previous installation types or designs.The reversible polarity connector reduces installer’s and customer’sinventory, installation time, and ultimately lowers their cost.

Such a connector employs a movable key that allows a user to reverse thepolarity of the connector without the need to open the connectorhousing. Additionally, the present connector can be employed inconjunction with a universal connector pin arrangement that also allowsa user to push forward or retract the MPO guide pins to assist inaccommodating the use of such connectors in both polarities, againwithout the need for opening the connector.

To this end, the present arrangement provides for a multi-fiber, fiberoptic connector, having a housing having a first end for receiving amulti-fiber fiber optic cable and a second end having openings for thefibers from the cable. First and second keys for setting the polarity ofthe fibers within the connector located on opposing sides of theconnector. The connector has either one of guide pins or guide pinreceiving holes for guiding the connection with a second connector.

The keys are movable between a first active position and a secondretracted position, such that when one of the keys is in the firstactive position, the fibers are presented within the connector in afirst polarity and when the second key is in the first active position,the fibers are presented within the connector in a second polarityreversed from the first polarity.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention can be best understood through the followingdescription and accompanying drawings, wherein:

FIG. 1 is a schematic view of a typical fiber optic arrangement of fiberoptic equipment and connectors;

FIGS. 2A-2D are a schematic view of fiber optic arrangements andpolarity configurations;

FIG. 3 shows a prior art fixed key MPO type connector;

FIGS. 4A and 4B show a reversible polarity connector, in accordance withone embodiment;

FIG. 5 shows two reversible polarity connectors in an adapter, inaccordance with one embodiment;

FIGS. 6A and 6B illustrate an exemplary fiber optic arrangement makinguse of reversible polarity connectors, in accordance with oneembodiment;

FIG. 7 shows a reversible polarity connector with retractable guidepins, in accordance with another embodiment;

FIG. 8 shows a reversible polarity connector with retractable guidepins, in accordance with another embodiment;

FIG. 9 shows a reversible polarity connector with retractable guidepins, in accordance with another embodiment; and

FIG. 10 shows a reversible polarity connector with retractable guidepins, in accordance with another embodiment.

DETAILED DESCRIPTION

In one embodiment of the present arrangement as shown in FIGS. 4A and 4Ba connector 10 is provided at the end of a multi fiber cable 12.Connector 10 has a housing 14, guide pins/guide pin openings 16 and keys18A and 18B. The housing 14 has a passageway 22 extending between afirst end and a second end. It is noted that connector 10 is shown withguide pin openings 16 (female) but all of the features of the presentarrangement are equally applicable to male/pins extended connectors 10as well.

As a basic explanation the “key” sets the order for which the fibers inconnector 10 are presented to an additional opposing connector 10. A keythat is ‘active’ is one that is in position to engage with an adapter.If a key is said to be reversed then it means that the key on theopposite side of the connector (that being the one that was notpreviously ‘active’ is now ‘active’. If connectors of both regular andreversed active keys are compared, it would be found that the fibers inconnector 10 are presented to an opposing connector in opposite order.The setting of the key 18 is what sets the polarity (arrangement offibers from cable 12) for connector 10 from the perspective of anopposing connector.

Thus, as shown in FIG. 4A, key 18A on the top of connector 10 is in aforward extended position. As shown in cut-away FIG. 4B, key 18A on thetop of connector 10 is in a forward extended position with key 18B onthe bottom of connector 10 in the retracted position within housing 14.Such an arrangement allows for keys 18A and 18B, on both sides ofconnector 10 and in respective first slot 24A and second slot 24B, to bealternately extended and retracted in order to achieve the desiredpolarity without disassembling the connector body. When cable 12contains at least one of these connectors 10, keys 18A and 18B on topand bottom can be adjusted to determine whether the assembly (cable witha MPO connector on each end) is a ‘Method A’ or ‘Method B’ as referredto in the standards.

Applicants note that there are two keys 18A and 18B on connector 10 sothat a fiber optic segment having two connectors 10 on either end mayexhibit both A & B polarities options. When a user wants a fiber opticsegment to be polarity A, the user simply sets the keys 18A on the topsof connectors 10 on both ends of the segment to the same setting, i.e.both keys 18A forward and active with both keys 18B retracted withinhousing 14) so that fibers exhibit the same presentation order on bothsides of the fiber optic segment. To reverse to method B polarity, oneof the keys such as a key 18A on one of the two connectors 10 isretracted into housing 14 and the other key 18B on that same connectorsis pushed forward to active. This allows for the polarity of a singleassembly or cable to be changed from A to B or B to A.

When keys 18A or 18B are retracted, nothing physically changes withfibers 12 in connector 10. Rather, the only change with connector 10 isa flipping of the order fibers 12 are presented to opposing connectorsbecause the active or forward key 18A/18B is switched from one side ofconnector 10 to the opposite side.

It is noted that nothing is moving within housing 14. Fiber positionnumber is always referenced by holding the key up and looking from leftto right. By having two keys 18A/18B on opposing sides of connector 10with the ability to activate one key or the other, this changes thedefinition of “up” for that connector. In other words with two movablekeys 18A and 18B on connector 10 and the ability to easily change whichkey is active (used to determine which way is “up”) a user can reversethe order of the fibers presentation on a connector 10 on one end of anassembly only, switching the segment from a Method A to a Method B orvice-versa.

Moreover, in the cut away example FIG. 4 b , connector 10 shows top key18A activated (extended out) and bottom key 18B retracted back intoconnector 10. As is evident from FIGS. 4A and 4B, keys 18A and 18B canbe used to change the polarity of connector 10 without the need foropening any part of connector 10, such as housing 14, unlike the priorart configurations.

As shown in FIG. 5 , which shows two connectors 10 fitted into anadapter 20. Such keys 18A (only top keys 18A are visible in FIG. 5 ) canbe operated by simply sliding key 18A forward and backward, or bypressing the key below the surface of the housing and lockingarrangement, located towards the front of housing 14 of connector 10.Each key 18A and 18B can thus be operated independently withnon-specialized tools and without disassembly of the connector, as thetab for keys 18 is accessible through a top opening 26 in at least partof the housing 14. It is noted that in FIG. 5 , such a tab for adjustingkeys 18, during a connection to another connector 10 via adapter 20,would actually fit within adapter 20. The other slide mechanism shown inFIG. 5 is related to another feature regarding an adjustable guide pinarrangement discussed in more detail below.

One exemplary arrangement for demonstrating the usefulness of connectors10 is shown in FIGS. 6A and 6B. In FIG. 6A a first equipment #1 is shownconnected to a second equipment #2 using five spans of fiber with MPOtype connectors on such spans at four locations (#1-#4). That is, ateach location #1-#4, there is an adapter 20 and two opposing MPOconnectors, one for each segment on either side of the adapter. Theconnectors at points #1 through #3 each maintain the same polarity fromthe prior segment (Method A polarity), and at connector #4 the polarityreverses (Method B polarity) before entering equipment 2 as shown in thefigure.

Turning now to FIG. 6B, assuming that owing to some required connectionchange, equipment #1 now needs to be connected to equipment #3 at adifferent location instead of equipment #2. As a result the thirdsegment of fibers after location #2 and their connector facing segment 2on the opposing side of location #2 now needs to be reversed in polarity(Method B) whereas in the prior FIG. 6A arrangement (connected toequipment #2) that same connector/segment would have simply retained thesame polarity (Method A). As a practical matter, in the prior art, aninstaller or user would have had to replace the fiber segment 3 with anew patch fiber segment having a different (opposite) pre-terminatedfixed polarity connector to fit into the adapter at location #2 in orderto change the polarity of the connection now entering into equipment 3.Or, using prior art connectors that could change polarity, the userwould have to open the housing of the connector on the third fibersegment after location #2 and change the polarity, possiblydamaging/diminishing that connector and the fiber connections therein.

However using the present arrangement, assuming the connector for fibersegment three exiting location #2 was a connector 10 according to thepresent arrangement, connector 10 could simply be removed from theadapter 20 at location #2 have the appropriate key 18 retracted/movedforward, and reinserted into the adapter as shown in FIG. 6B, changedfrom Method A to Method B polarity.

In another embodiment of the present invention as shown in the followingFIGS. 7-10 , in addition to connector 10 being a reversible polarityconnector 10 using keys 18A and 18B as explained above, such connectors10 may also have a retractable guide pin arrangement 50 so thatconnector 10, in addition to having reversible polarity also canexchange between male (extended) and female (retracted) guide pinconfigurations.

As shown in FIG. 7 , connector 10 has a guide pin arrangement 50 shownin the extended male configuration. Guide pin arrangement 50 includes anattached retraction tabs 52 (one opposing side not shown) located oneither side of the connector. In FIG. 8 connector 10 has the sameretractable guide pin arrangement 50 shown in the extended maleconfiguration. In the embodiment shown in FIG. 8 , guide pin arrangement50 includes attached retraction tabs 52B located on the top of connector10.

In FIG. 9 connector 10 again has the same retractable guide pinarrangement 50. In the embodiment shown in FIG. 9 , guide pinarrangement 50 includes a single attached retraction tab 52C located onthe top of connector 10 in between a bifurcated arrangement of tab(s)18C to change the polarity of key 18A. In FIG. 10 connector 10 has thesame retractable guide pin arrangement 50. In the embodiment shown inFIG. 10 , guide pin arrangement 50 are spring biased via biasing springs51 (internal) and held in position using pin locks 54 on top ofconnector 10.

As an example of how the embodiment with retractable pins 50 supplementsthe usefulness of the reversible polarity of connector 10 using keys 18,Applicants note that standard equipment typically has pins in it, butsome of the components in given channel (e.g. a 4 connector channel ofpatch cord, trunk, patch cord, trunk, patch cord etc.... ) will havepins and the rest will not since it is always required to mate a male toa female. So if a user were to add or subtract fiber segments/elementsfrom the channel, even if the polarity can be changed, they may or maynot end up with connectors with pin arrangements that can be matedtogether. By adding switchable guide pins this possible drawback can beovercome.

While only certain features of the invention have been illustrated anddescribed herein, many modifications, substitutions, changes orequivalents will now occur to those skilled in the art. It is therefore,to be understood that this application is intended to cover all suchmodifications and changes that fall within the true spirit of theinvention.

We claim:
 1. A fiber-optic connector comprising: a connector bodyincluding a housing with a top surface and a bottom surface, the topsurface and the bottom surface being joined together by two opposingside surfaces of the housing; the housing having a top slot and a bottomslot thereupon along a longitudinal axis, the top slot and the bottomslot being provided on the top surface and the bottom surface,respectively; a first key structure slidably positioned within the topslot; and a second key structure slidably positioned within a bottom;wherein the first key structure is slideable relative to the top slot onthe housing and configured to remain within the top slot, wherein thesecond key structure is slideable relative to the bottom slot on thehousing and configured to remain within the bottom slot, wherein, inoperation, a polarity change of the fiber-optic connector is carried outby sliding the first key structure within the top slot toward a frontend of the housing and retracting the second key structure within thebottom slot away from the front end of the housing without removal ofthe first key structure and the second key structure from the housingfor the polarity change.
 2. The fiber-optic connector of claim 1,wherein the fiber optic connector includes two or more optical fiberssupported therein.
 3. The fiber-optic connector of claim 2, wherein thefiber optic connector includes two optical fibers supported therein, afirst of the two optical fibers carrying a transmission signal and asecond of the two optical fibers carrying a receiver signal, therebysetting a polarity of the fiber-optic connector.
 4. The fiber-opticconnector of claim 1, wherein a portion of the first key structure and aportion of the second key structure remains attached to the housingduring the polarity change.
 5. The fiber-optic connector of claim 1,wherein the first key structure and the second key structure areslideable relative to the housing parallel to the longitudinal axis. 6.The fiber-optic connector of claim 1 further comprising: a lockingarrangement for each of the first key structure and the second keystructure.
 7. The fiber-optic connector of claim 6, wherein the lockingarrangement is located at the front end of the housing.
 8. Thefiber-optic connector of claim 1, wherein the fiber optic connector is amulti-fiber fiber optic connector.